Shares of pharmaceutical company Bristol-Myers Squibb Co. (BMY) - Get Report    are up 0.8% Monday on a report that hedge fund Starboard Value took a stake in the company last month, according to Bloomberg.

The report didn't provide a dollar value for the investment. 

A phone message to Starboard and  a phone call and email to Bristol-Myers Squibb to verify and seek comment on the report weren't returned to TheStreet over the weekend. Bloomberg also reported no official comment from either company.

The report follows last month's news that Bristol-Myers Squibb would buy Celgene Corp. (CELG) - Get Report in a cash-and-stock deal with worth about $74 billion.

Bristol-Myers has fallen more than 18% over the past 12 months, including a more than 2% drop since the beginning of the year. On Monday the shares fell 1.9% to $50.83.

Starboard Value was formed in 2002 by Jeff Smith and Mark Mitchell, and, later, by Peter Feld. The fund's healthcare holdings include managed care specialist Magellan Health Inc. and Perrigo Co.